The present invention relates generally to an electrical connector and, more particularly, to an insulation displacement connector for flat cables.
Mass termination techniques utilizing insulation displacement connectors have been common place throughout the industry. Such techniques allow rapid interconnections to be made between the conductors of a flat cable and the contacts of the connector by simply clamping the cable between the connector cap and housing thereby forcing the cable conductors into slots in the contacts. Generally the termination ends of the contacts are in the form of slotted plates. U.S. Pat. No. 4,118,096 and Dutch Pat. No. 67298 disclose a variety of slotted plate type of insulation displacement contacts. The slotting of the contact produces what might be considered to be a double tine termination system in which each tine of the slotted contact is located on opposite sides of the cable conductor. It will be appreciated that because of the double tine system there is a limitation on the closeness of the spacing of the contacts and, therefore, miniaturization of cable/connector assembly. U.S. Pat. No. 4,118,096 teaches forming lateral projections on the tines that engage the sides of openings in the connector cap to increase the pressure applied on the conductor by the tines.
U.S. Pat. Nos. 4,190,942 and 3,816,818 disclose insulation displacement connectors in which each contact is in-line or on-edge with respect to the conductors of the flat cable as opposed to being perpendicular to the conductors as in the conventional slotted plate type of contact. In the in-line type of insulation displacement contact a slot in the contact is not produced by the blanking or removing of material as in the conventional slotted plate contact, but rather is produced by slitting a generally flat plate and then offsetting the tines or arms which are produced by the slit. Connection of the conductor to the contact is achieved by inserting the conductor into the slot formed by the offset tines. This type of contact allows a closer center-to-center spacing of the contacts in the connector housing so that the length of the connector may be reduced.
In each of the contacts discussed above the resilient tines or arms formed by the slots or slits, respectively, form a pair of cantilever beams which spread outwardly when the conductor of a flat cable is pushed downwardly into the slot provided between the tines. In the case of the conventional slotted plate contact, the width of the cantilever beams at the root of the beams is relatively great as compared to the thickness of the metal sheet from which the contact is formed so that the cantilever beams have substantially high strength. In contrast, with the in-line type of contact in which a flat plate is simply slit and the thus formed tines are offset from each other, the thickness of the cantilever beams at the root of the beams is only that of the thickness of the gauge of the sheet metal used to make the contact. As a consequence, the strength of the beams is substantially reduced. As a result, the electrical connection made between the contact and the conductor pushed between the tines is not as strong or reliable as when using the slotted plate type of contact. It is the object of the present invention to provide means for making the in-line type of insulation displacement contact stronger and more reliable.